Throne of Glass was a bit underwhelming for me compared to The Assassin's Blade. I enjoyed it and still love Celaena but it was missing something. I think that big thing was Sam. I loved him so much I had a hard time getting into the next one.
Celaena has been in Endovier for a year. Beaten and seen unforgivable things she is now being forced to partake in a competition to become the kings champion. The only chance of freedom. Celaena trains hard to win. But when the other champions start dying around her there's clearly something else going on in the castle.
A lot of this wasn't nearly as exciting. A lot of build up to get to the competition. I definitely liked the ending more than anything. Chaol and Dorian are pretty great characters as well, just not as good as Sam.
I think a part of why I didn't like this as much was because Celaena seemed the same as she was entering Endovier. And I was expecting a big change for how bad they made the death camp seem. I would have loved more flashbacks to the actual camp as well.
Still fun though, and still enjoying reading a new fantasy series.